## Measuring your Sake – Part One: the Hydrometer and SMV

Measuring your Sake – Part One: the Hydrometer and SMV

In this series on Measuring your Sake I will cover how to measure all the key characteristics of sake. These include:

–          Nihonshudo a.k.a. Sake Meter Value (SMV) and specific gravity
–          Alcohol percentage by volume
–          Sando or Acidity
–          Amino Sando or Amino acid levels

For Nihonshudo or SMV all that is needed is a hydrometer. The most commonly available hydrometers are for specific gravity though you can find other metrics. To simplify this discussion I will stick to specific gravity and SMV. A discussion of these other metrics is in the article: Nihonshu-do (日本酒度) or Sake Meter Value (SMV).

So, what are we talking about when we talk about specific gravity? Well, specific gravity is a measure of the density of a liquid compared to the density of distilled water at 60F. But what does that mean?

## Nihonshu-do (日本酒度) or Sake Meter Value (SMV)

This article discusses Nihonshu-do (SMV), Buame, Plato and specific gravity for sake Brewing.

Nihonshu-do also known as SMV is the way we measure the sweetness to dryness level of a sake. The word nihonshu-do itself can be broken down into three words Nihon Shu Do with the English counter parts being Japan Alcohol Degree (as in position on a scale). So Japanese Alcohol is Sake and Degree or Meter Value taken together represent the main metric used to characterize sake. At first glance this measure is relatively simple and this is as it should be for sake aficionados. A -4 SMV value for a sake implies it is quite sweet while a value of +10 would be very dry. Its use in brewing reflects its more complicated nature.

SMV was originally based on the Heavy Baume scale created by a Frenchman in the late 1700s. However, the heavy baume scale is only valid for liquids that are equal or heavier than water and this is not the case for sake. For this reason nihonshu-do has the same slope as the heavy baume scale but is not the same. When nihonshu-do and heavy baume are used to evaluate the degree of sugar in water they directly represent the amount of sugar by weight in the solution. While the baume scale is pretty much obsolete today, similar scales like the Balling, Brix and Plato scales are all attempts to measure the amount of dissolved solids in solution with more accuracy, i.e. the grams of solids in 100 grams of water. However, where Baume was working with a sodium chloride solution Balling, Brix and Plato specifically worked with sucrose solutions. Continue reading “Nihonshu-do (日本酒度) or Sake Meter Value (SMV)”